Add `ToArray(Image image)` to `ImageHelper`

[AndreasReitberger]

public static byte[] ToArray(Image image)
{
    if (image?.Source is not StreamImageSource streamImageSource)
        return [];

    using MemoryStream memory = new();
    Stream? streamFromImageSource = streamImageSource.Stream(CancellationToken.None).GetAwaiter().GetResult();
    if (streamFromImageSource is null)
        return [];
    streamFromImageSource.CopyTo(memory);
    return memory.ToArray();
}